Canceled decks of used playing cards from the Aria Casino in Vegas are now at some of the 99-Cents Only stores. Yep, 99.99-cents a pack. On eBay they're selling for $4-$5 a pack. What was curious is that they came in larger boxes marked "Harrah's LV" so I think these came from a supplier or liquidator that works with the casinos. The packs had a seal indicating they were used at Aria. In hindsight I should have bought a pack to see what the "cancellation" was. Usually they put the pack into some kind of cutting machine and a corner of the deck is cut off.
I have a lot of canceled casino dice and a small circle is pressed into the side with the four pips. I've heard about dice being drilled through with a hole but haven't seen that. I think that's too much trouble -- the circle in the center of the four pips is obvious enough.
The cancellations are of course needed to prevent a cheat from introducing "extra cards" into a game or switching dice when, for example, one goes off the table. But besides looking for cancellation marks when a die goes off the table, the floorman or boxman is also checking the "serial number" as serial numbers change with various shifts, and he is also checking for damage such as a chipped corner.